1. Field of the Invention
This invention relates generally to compressors and, more particularly, to a method and apparatus for noise control in compressors used in refrigeration systems.
2. Description of the Related Art
Compressors generate a high-pressure level of gas pulsation at the compressor discharge port or passage. This high-pressure level is a leading cause of internal mechanism failure, such as, for example, check valves. Additionally, the high-pressure level is a main source of noise and vibration problems.
Contemporary devices have attempted to address these problems with compressor mufflers that are reactive, i.e., designed based upon the volume change to reflect acoustic waves. As shown in U.S. Pat. No. 6,280,154, the scroll compressor has a cylindrical housing having welded at the upper end thereof a cap and at the lower end thereof a base. The cap is provided with a refrigerant discharge fitting which may have the usual discharge valve therein. A transversely extending partition is affixed to the housing by being welded about its periphery at the same point that the cap is welded to the housing. While such reactive mufflers can suppress some gas pulsation, they are of limited use where a more compact muffler is required or where a refrigerant requires a higher operating pressure.
Accordingly, there is a need for a compressor muffler that can withhold higher gas pulsation, even at higher operating pressures. There is a further need for such a muffler that can generate lower noise and vibration within a desired physical size and/or shape limitation.
It is an object of the present invention to provide a compressor muffler that absorbs sound generated from gas pulsation.
It is a further object of the present invention to provide such a compressor muffler that efficiently absorbs such sound over a wide range of frequencies.
It is yet a further object of the present invention to provide such a compressor muffler that provides a compact size.